/Engine/Source/Runtime/InteractiveToolsFramework/Public/InteractiveToolsContext.h
Replace the internal functions that are called to create/destroy the sub-objects owned by the ITC.Bydoing this, clients of the ITF can provide their own subclass implementations, or do other custom setup/teardown as necessary. See comments above CreateInputRouterFunc below
virtual void SetCreateInputRouterFunc ( [TUniqueFunction](API\Runtime\Core\Templates\TUniqueFunction)< [UInputRouter](API\Runtime\InteractiveToolsFramework\UInputRouter) *(const [FContextInitInfo](API\Runtime\InteractiveToolsFramework\UInteractiveToolsContext\FContextInitInfo) &)> Func )